Various radio channel types exist today for use by portable radio transceivers, global system mobiles (GSM) speech channels, general packet radio service (GPRS), Bluetooth and wireless local area network (WLAN) being examples of such channel types. Furthermore, the universal mobile telephone system (UMTS) allows the transfer of audio-visual information in both directions between portable radio transceivers. The term now adapted for portable radio transceivers of the UMTS standard is mobile station (MS), and this term is used hereafter to describe a mobile radio transceiver capable of communicating in any system.
With many MSs being equipped to communicate with two or more different channel types, it has become common for a user of an MS to have to decide which type of communication channel to use, which can constitute an inconvenience.